Microgrid refers to a small power distribution system composed of distributed generators and energy storage system and so on. It is an autonomous system capable of self control, protection and management. Microgrid can run with the main grid jointly or run in isolation, and it is an important constituent part of the smart grid. The basic goal of optimal scheduling of microgrid is to reasonably and effectively arrange the output of each distributed generator, and the transaction power with the main grid by certain control strategies under the premise that the system load requirement of the microgrid is met, so as to minimize the operation and maintenance cost, and the emission cost of the whole microgrid.
With the increasing development of human society, energy and environment problems are becoming more prominent. In order to secure energy safety and transform toward a low-carbon economy, various countries take the development of electric vehicle (hereinafter referred to as EV) as an important strategy to deal with the energy source and environment problems. In China, the EV is listed as one of the strategic emerging industries and its industry application is vigorously promoted. The battery of EV as a mobile-decentralized energy storage device, can not only absorb power from the main grid, but also feed power back to the main grid. Therefore, EV can participate in the operation and control of an electric power system. For the main grid, the battery of EV could play a role of load shifting and improve the stability of the power grid; and for a user, a reasonable arrangement of charge and discharge of EV could reduce the cost for electricity. Besides, EV could also provide the user with a reliable reserved power source, so as to reduce the loss caused by power outages.
The existing optimal scheduling methods considering EV accessing microgrid often do not consider the cost of depreciation from the charge and discharge of EV battery, which is negative for economically managing the EV battery. In real life, the time of an EVs accessing the microgrid, the state of charge of EV batteries when accessed, and the minimal state of charge of batteries required by EVs when leaving the microgrid are different, such differences are not considered in the optimal scheduling model of the existing scheduling methods considering EVs accessing the microgrid, which is negative for the optimal load scheduling of the micro grid containing EVs in practice.